I really dug the New Krypton era. It's a pretty big chunk o' books that probably started with Johns Action Comics run and eventually led to a pretty massively big triangle era. I loved the way it brought together so many mostly disparate aspects of the Superman mythos into something huge. Honestly, I think it was so good that it makes it hard to pick up post flashpoint Superman, which I did for a while. Honestly, I can dig some of the changes to Superman himself (even if I don't love all of them) but the Superman corner of the DCU just seems so much less in every imaginable way now.